Nickel carbonyl, Ni(CO)4 was first produced by the reaction of metallic nickel with carbon monoxide by Mond in the early part of the 19th century. Today, one of the major industrial processes for making metallic nickel is based on the production of Ni(CO)4 and subsequent thermal decomposition thereof to Ni and CO. One known commercial process operates at about 180° C. and a CO pressure of about 70 atm. It is known that the CO pressure may be reduced when the reactant nickel is catalytically activated.
Activation of the metal has been observed in the presence of mercury (1, 2), sulfur in the form of H2S (3, 4), hydrogen (5, 6) or carbon (7). It has been suggested that the high initial rate of formation of Ni(CO)4 and the subsequent decline to a steady state value is the result of a rapid decrease in the number of activated reaction sites which are produced upon heat treatment of the sample (8, 9, 6). A study of surface changes during carbonyl synthesis suggests that the maximum rate is associated with fundamental changes in the defect structure. All of the above methods use catalytical activation of nickel in the presence of CO.
However, it can be readily appreciated that processes that at atmospheric pressure can produce nickel, particularly, activated nickel for subsequent reaction with CO would provide significant capital and operating cost advantages.
Further, it can also be appreciated that processes that enable Ni(CO)4 to be manufactured at a sufficient rate as to obviate the need for storage in order to build up a sufficient supply for practical, efficient use in a subsequent nickel deposition process, would also offer significant capital and operating cost savings. To-date, in commercial operations rate limitations on the production of Ni(CO)4 require such storage facilities and operations.
There is, therefore, a need for an improved method of Ni(CO)4 production which is operably at atmospheric pressure and which is of a sufficient rate as to negate the need for storage of the Ni(CO)4 prior to use in a subsequent deposition process.